If you ever needed to model, analyze or simulate a process, there is a fairly big chance that you’ve found yourself working with something called SIMPROCESS. Since this isn’t that kind of software that can be found on everybody’s computer, you’re either a student at a University, or working in a company that wants to simulate their production cycle, for example. Now, assuming that you’re trying to simulate something a bit more complex than a donut stand, I’m quite sure you’ve been forced to use the built in Expressions, which tend to generate a myriad of illogical complications, without giving you the proper lead as to where the problem lies. Additionally, when trying to look-up the problem in the manual, you don’t find anything useful, or at best a hint that what you’re trying to do is indeed possible, but there is no explanation on how to actually do it. What is left is to either learn it by yourself through trial and error, or by reading this guide I put together, and maybe finding what you’re looking for.

Basics

Almost every object that can be placed within the simulation contains it’s own Expressions tab, which gives you further possibilities to write your own code snippets for various actions (Start/End of the simulation, Accept/Release Entity, and others) that execute when that specific action happens. The programming language used for the expressions should be powerful enough for most of the problems, but if that’s not the case, you have the possibility to include your own external scripts.

Syntax

Let’s start at the beginning. Simprocess Expressions is a script language, so you can forget about classes and methods right away. It comes with some inbuilt functions, that are very handy for accessing data about various Entities and processes during the simulation at specific occasions. You can find all of them on the left side of the expression view, but it takes some time to get a hold of what some of them do, and especially how to use them. This is where the validate button comes in. Click it as often as possible! It doesn’t tell you what’s wrong, but at least you know you’ve done something that won’t work.

Here comes the juicy part of this guide, the stuff that makes this scripting language so different and in some cases even confusing at first.

Data type definition

If you ever delved into a programming language, you’re probably used to start each data type definition by first declaring the data type, and then the name of the variable or constant. Well, here is the other way around.

    boozeMoney : REAL;
    boozeMoney := 10.95;

Also notice the way variable values are defined. In Simprocess = is the equivalent of == (used for comparison), while := is used for defining the value (instead of = which is more commonly used for this kind of operation).

Another thing you need to watch out for. When you define the value of a REAL, if it’s a rounded number, let’s say 5, always write it in the decimal representation: 5.0. The same applies to all instances where you handle real numbers.

Comments

One of the most important aspects of every programming language is the ability to write comments. Most languages use a common denominator for comments, the double slash // or /* comment here */, some of them however use different ones # or ‘, and there are programming languages that use yet another different approach. Simprocess is one of them.

    { Can't wait for the evening!!! }

Statements

As we’ve seen, curly brackets are reserved for comments, therefore we don’t use them after a statement, that is why we need to close each one with a corresponding end statement. Actually, we don’t use any kind of brackets at all! Instead we use a new line to separate the condition from the code that executes when the condition is true.

IF time = 2100
   partyMode := TRUE;
END IF

Apart from IF, there is also ELSE, ELSIF and WHILE, and probably also FOR, however I’ve never used it. In case you need to form a more complex decision making structure there is no SWITCH statement to help you, so you have to recur to the good old IF ELSIF ELSE strategy and nesting.

IF mood = "overjoyed"
   drinksOnMe := TRUE;
ELSIF mood = "furious"
   rationalBehaviour := 0;
   wreakHavoc := TRUE;
   getArrestedProbability := 78;
ELSE
   IF friendsNearby > 0
       engageInChat := TRUE;
   END IF
   drink := "beer";
END IF

Random number generator

It took me quite some time to figure out this one. The manuals are not really helpful in this regard, and this functionality is not even listed anywhere. There are actually two functions, one is for integers and the other for real numbers. The setup is pretty straightforward, you just need to enter the correct mathematical distribution and it’s parameters, and store the result in a variable of your choice.

If you’re looking for a random number represented as an integer, you’ll need to use a discrete distribution. And since we’re trying to make the random function as random as possible, the discrete uniform distribution is the way to go.

    myLotteryTicket := DrawIntegerSample("Uni(0, 10)");

The same applies when you’re looking for a real number, you just have to use the appropriate function.

    luckMeter := DrawRealSample("Uni(0, 1)");

You can of course use the DrawIntegerSample and DrawRealSample function in combination with any of the other 24 mathematical distributions for other purposes and needs.

Entities and Resources

Whenever an Entity passes through an object, you can gather information about that specific Entity, by using predefined attributes, or by attributes you’ve specified and trigger actions based on what you learned.

Resources are general and follow some basic rules. There are a couple of elements that you can configure to handle resources, but if you’d like to fine tune the process, you’ll need to use the expressions.

IF Entity.Name = "Dave"
   Entity.pMoney := Entity.pMoney - 5.0;
   IncreaseCapacity("barMoney", 5.0);
ELSIF Entity.Name = "Boss"
   Entity.pMoney := Entity.pMoney + 88.0;
   DecreaseCapacity("barMoney", 88.0);
END IF

Output

When running a simulation you probably won’t ever need to use it since it has a considerably big effect on the speed of the simulation, but it comes very handy when you’re debugging.

    OUTPUT("Yeeha, this party rocks!");

Conclusion

I realize that this guide doesn’t show all aspects of the Simprocess Expressions, but I feel I’ve covered most of the topics a beginner would stumble upon when fiddling with this software. And anyway, this scripting language isn’t meant to be overused. I’ve tried building a casino simulation with a few colleagues using mostly expressions to simulate four most popular casino games (Roulette, Craps, Blackjack and Slots) including the decision making process of the clients and the simulation (scheduled to simulate 1 year) took nearly one hour to complete. Hopefully this will be useful to someone.

If it wasn’t obvious to some people before, it’s painfully evident now that there is something awfully wrong with these youngsters, and our society as a whole, which permits riots like this to happen. I wouldn’t say anything if this would be a protest against a dictatorship, or against a law or some other kind of enforcement that would hinder our human rights, or in any other way endanger our rights and lives. But this? This was a protest against a law that would actually benefit many students (both life/injury and payment insurance, recognition of work experience, earlier start of pension accumulation) and allocate more money for scholarships! Yes, it has it’s downsides, but they mostly affect the Student organisations of Slovenia and those that are now reaping big profits from the field of the Student work. And what’s more, the law hasn’t even been wrapped up yet and sent into the National Assembly for vote! The talks with the Student organisation of Slovenia were still open!

Going out, shouting “f**k the government”, littering Ljubljana and throwing objects at the police and the Parliament and even setting fires for something like this is just insane and stupid. It throws a bad light on the student population as a whole, discredits those that try to make some progress with peaceful protests and talks and renders all the previous efforts meaningless. Not to mention that now everybody is talking only about this shameful event and not about the very issues the protest was organised for.

And seriously, making so much damage to the parliament? For Christ’s sake, it’s only 19 years since we’ve achieved our independence, and kids of those who fought for our freedom go and deface the very symbol of it?

Enjoy!

Initially I had some thoughts about whether or not should I go, but in the end I grabbed the opportunity and departed. And this was, without any doubt, one of the best decisions in my life. I had so much fun, met many new wonderful friends and scouts from all over Europe. It was a week filled with various captivating activities, interesting discussions and chats, and many great moments spent together with other scouts. Simply an amazing experience.

It’s only a few days since I returned home from IMWe, but I’m already filled with sadness and sorrow for not being able to be with my new friends. Now I understand why people keep returning to Rieneck for years and why aren’t many new faces at this event each year.

This is such a fantastic experience, that is much much more than just a plain international scout gathering. IMWe is a family, which I feel being part of now as well. That’s why I’m already impatiently counting the days towards IMWe 2011, which is sadly still far in the future. Well, let’s hope there will be a reunion somewhere in the vicinity, which I’ll be able to join.

As it happens, there was an occasion last week, when I suddenly felt (out of boredom) that I need to write a poem about a guy that likes to watch the stars. Since the title might imply that this song is boring, I must disappoint you, this is not the case (well, at least I laughed when writing it), and I feel obliged to warn you, that it’s not a song to be read to children as a lullaby.

Uncle Tony watched the stars

Uncle Tony watched the stars,

while out shopping, or stealing cars.

Looking up with an intensive gaze,

his voice was clear, his eyes ablaze.

Uncle Tony watched the stars,

drinking whiskey in classy bars.

Racing ’round in his pickup truck,

with loaded guns, and explosives packed.

Uncle Tony watched the stars,

shooting people, starting wars.

Walking around in his Cowboy attire,

leaving mayhem and a ball of fire.

Uncle Tony watched the stars,

chased by the police in their fastest cars.

With two helicopters right behind,

a ray of hope for the humankind.

Uncle Tony watched the stars,

from his cell, through iron bars.

Heavily guarded in his prison,

will he change and see the reason?

Uncle Tony watched the stars,

his mind unchanged, still wishing wars.

Until the end of the great debate,

to decide upon his sorry fate.

Uncle Tony watched the stars,

on a spaceship, bound for mars.

Where he could see the stars up-close,

he shed a tear, and blew his nose.

He finally got for what he craved,

everyone happy, our existence saved.

Well, looks like you safely battled your way through this unusually large page. Congratulations! I guess you’re probably wondering who uncle Tony is? The answer is quite simple, no-one. At least no-one from the real world. And why uncle? Because it sounded better than “some guy Tony”. Now who is uncle Tony in my fictional world, well… that is to be discovered in some future song.

But it really makes you think, how is such a disproportionate ratio between legitimate comments and spam even possible? Especially when you take into account that most of those spam messages (approximately 60% in my case) are not made by bots, but from real people that try to bring traffic to their own website. I understand that my website is quite attractive for advertising through comments since Time Recursion is a do-follow website, but guys, come on! At least write something that’s related to the post you’re commenting! If you’ll insert your website address in the Website field, you’ll still get the PR juice and if the content of your comment is related to the article I’ll approve that comment without hesitation, you can be sure of that. After all, I’m always eager to get some feedback on what I write.

Yesterday I was suddenly struck by an urge to grab my guitar and play some music. The thing is, my guitar’s at home, so I borrowed one from one of my friends for a short time. It’s funny though, I’ve never felt the need or such a strong desire to play this instrument before. It was always either because I had to practice, or because I didn’t have anything better to do. This time it was the other way around. And it still is, so I’m quite anxious to come home this Thursday and put my hands on my guitar. Might aswell take some time to learn to play some new songs.

And let’s not forget about the upcoming holidays! Oh, yeah, I foresee some good things will happen during the next week and a half. If nothing else, I won’t have much work for my university, and I’ll finally be able to go to a Magic: the Gathering session with my friends. I can’t believe it’s been more than a month since we last played MTG, plus, there’s a couple of stories I’ve been planning to write and publish on my blog since this summer, but haven’t got around doing it. Maybe I’ll finish writing them this time, we’ll see.

This is good in a way, since we have instant access to almost everything we need wherever we go, but what happens if we loose, misplace, or God forbid, someone steals our precious cellphone? In that case my friends, we’re on a roller-coaster that has a stinky pond as a final stop, in other words, we’d be better off losing our wallet.

But fear not, not everything is lost. Thankfully there exist programs that’ll help you find your lost/stolen electronic property and possibly even bring the thieves to justice. How do they work? Most smart phones have GPS technology, which can be used in conjunctions with the retrieval software to send information about the device’s location. If that’s not the case, it’s possible to define the phone’s location through signal strength analysis from the few nearest stations. It’s less precise, but nonetheless very helpful. But what about flash drives, cameras or even laptops? It gets a bit harder with those, but essentially, you receive the IP address of the computer they’ve been connected to, with which you can (usually it’s the police who does that), if you get a permit, obtain the postal address of the person it was used by at that time.

Most of such services require an annual fee to use their software, but there are some other alternatives you might want to consider as well. For example, JustStolen is a service set up by a group of police officers, that offers you a place to store your gadget’s serial identification number, which makes the process of finding the owner of stolen property quicker and easier.

On the bright side, I’ve finally sweeped off the dust off my guitar and started practicing again. After almost two years of hiatus I’m actually pleasantly surprised that I still remember all chords that I knew before and can find most of their scales without having to look them up. There is one downside though. My fingers aren’t used to the metallic strings of my acoustic guitar anymore, so the progress is quite slow. It’ll also take some time to regain my previous agility in changing chords and staying in rhythm, which is proving to be quite a pain in the ass right now.

The moving of mladi.net from lunarpages to a more reliable host is also something that is giving some variety and dynamics to this summer. Apparently it’ll be up to me to come up with a good design to replace the current one and to better reflect our movement to a completely new platform as well. I haven’t really done much web designing in my life, the one so far (planthefuture.info) sucks, and the promised redesign of Time Recursion appears to be stuck somewhere on an expedition in Himalaya, wearing only shorts, a t-shirt and some old, holey All-Star shoes. Though the concept I came up with so far, looks quite good in retrospect to everything else I’ve made up to now.

Oh, and there’s also “getting familiar with php-symfony” on my to-do list, so I can help my buddy with the new platform for the website.